Currently, the vacuum magnetron sputtering technology is extensively used in the film coating field. The magnetron sputtering device in the prior art is provided with a magnetic levitation track, on which the supporter for supporting the object to be processed is levitated. While the object on the supporter is being coated, the insulation pad disposed on the periphery of the supporter may be coated with metal film on its surface, which would result in abnormal discharge between the magnetic track and the supporter and seriously impact the quality of the coated film.